BLUE HILL METEOROLOGICAL OBSERVATORY
MILTON, MASSACHUSETTS
ELEVATION 635 FEET, 10 MILES SSW OF BOSTON, MA
 
DAILY DISCUSSION AND CLIMATE SUMMARY
SUNDAY, DECEMBER 21, 2014    
ALL TIMES ARE IN EASTERN STANDARD TIME
 
LIGHT SNOWFALL OVERNIGHT BRINGS 1.7 INCHES OF SNOW
LOW OVERCAST AND FLURRIES LINGER INTO AFTERNOON
 
A localized, ocean enhanced snow event yesterday afternoon into this
morning brought 1.7 inches of snow to the summit, the largest single
event total of the month so far.  The snow began sporadically early
yesterday afternoon, and steady snow ended around 7:30 this morning. 
A melted precipitation total of 0.19 inches was measured, which equates to
a snow to liquid ratio of about 9:1.  Despite an end to the steady snowfall,
overcast conditions have remained in place into this afternoon, along with
some snow flurries and light snow showers.  No sunshine has been observed
today.  This month continues to run well below average for sunshine, and
well above average for precipitation.  Temperatures have been steady in the
upper 20s to lower 30s throughout the day.  Yesterday was the first day of
below average temperatures in over a week, with this month running close to
two degrees above normal so far.
 
The winter solstice occurs at 6:03 P.M. this evening, marking the start of
astronomical winter.
 
Today's Observations:
 
7 A.M.
Weather: Sky obscured by light snow and fog
Temperature: 30F; Dew Point: 30F; Wind: NNE at 10 kts
Sea-level pressure: 30.30 ins. Hg, falling then rising                    
Visibility: 1/2 mile, light snow and fog
Snow depth: 2 ins.
6-hr max temp: 31F
6-hr min temp: 29F
6-hr precip (ASOS): 0.08 ins.
24-hr precip:  0.19 ins.
24-hr snowfall: 1.7 ins. 
BHO SA 1155 W3 X 1/2S-F 261/30/30/0210/030/ NEW SNW PST 24 HRS 1.7 INS/
8//// 4/002 53005 ASOS 60008 70020 MANUAL 70019 10031 20029
 
10 A.M.
Weather: Overcast stratocumulus 
Temperature: 29F; Dew Point: 29F; Wind: Estimated NNE at 3 kts,
Wind: Light
Sea-level pressure: 30.33 ins. Hg, rising then rising more rapidly
Visibility: 25 miles
3-hr precip: Trace
3-hr snowfall: Trace
BHO SA 1455 E7 OVC 25 271/29/29/E0203/033/ NEW SNW PST 3 HRS TRACE
WND LGT/ 8/5// 53010 MANUAL 6000/
 
1 P.M.
Weather: Very light snow, overcast stratocumulus, thin fog all quadrants
Temperature: 30F; Dew Point: 30F; Wind: N at 6 kts
Sea-level pressure: 30.29 ins. Hg, falling then falling more slowly 
Visibility: 10 miles, thin fog
6-hr max temp: 31F
6-hr min temp: 29F
6-hr precip: Trace
6-hr snowfall: Trace
BHO SA 1755 E7 OVC 10S-F 257/30/30/3606/029/ THN FG ALQDS PCPN VRY LGT
NEW SNW PST 6 HRS TRACE/ 8/5// 56014 MANUAL 6000/ 10031 20029

SUMMARY FOR SATURDAY, DECEMBER 20, 2014
 
TEMPERATURE (DEGREES F)
MAX.....32   NORMAL.....38
MIN.....24   NORMAL.....22
MEAN....28   NORMAL.....30
 
DEPARTURE FROM 30-YEAR NORMAL.........................-2
TOTAL DEPARTURE FOR THE MONTH........................+37 [+1.7 DEGREES/DAY]
 
HEATING DEGREE DAYS (SEASON JUL TO JUN)
TOTAL HEATING UNITS FOR YESTERDAY..............37  DEPARTURE...........+2
TOTAL HEATING UNITS FOR THE MONTH.............599  DEPARTURE..........-39    
TOTAL HEATING UNITS FOR THE SEASON...........1758  DEPARTURE.........-142
TOTAL HEATING UNITS LAST SEASON TO DATE......1919  DIFFERENCE........-161
 
PEAK GUST AND AVERAGE WIND SPEED (MPH)
PEAK WIND GUST FOR YESTERDAY..................21  NNE  AT  9:33 P.M.    
                   ASOS.......................24  NNE  AT  9:33 P.M.    
                   DAVIS......................22  NNE  AT  9:32 P.M. RMY 23
FASTEST MILE FOR YESTERDAY....................14  NNE  AT  9:30 P.M.      
MAXIMUM 2-MINUTE ASOS AVERAGE.................15  NNE  AT  9:33 P.M.     
MAXIMUM 2-MINUTE DAVIS AVERAGE................14  NNE  AT  9:28 P.M.     
AVERAGE WIND SPEED AND DIRECTION..............9.3 NNW     
                   ASOS......................10.1   
                   DAVIS......................8.3 N [358 degrees] 
                
PRECIPITATION (INCHES) THROUGH THIS MORNING (EST)
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M....0.19  DEPARTURE.....+0.03
                         ASOS..............0.20
TOTAL PRECIPITATION FOR THE MONTH..........6.04  DEPARTURE.....+2.80      
                         ASOS..............6.21 
TOTAL PRECIPITATION FOR THE YEAR..........53.80  DEPARTURE.....+2.03
                         ASOS.............54.40  
 
SNOWFALL (INCHES) THROUGH THIS MORNING (EST)
TOTAL SNOWFALL 24 HRS ENDING 7 A.M..........1.7  DEPARTURE......+1.1
TOTAL SNOWFALL FOR THE MONTH................2.3  DEPARTURE......-5.5
TOTAL SNOWFALL FOR THE SEASON..............11.0  DEPARTURE......+0.6 
 
PRELIMINARY CLIMATE SUMMARY FOR DECEMBER CALENDAR DAY DATA
DATA REPORTED:
DATE: MAX/MIN/MEAN/DEP/PRECIP/SNOWFALL/SUN(MIN.)/SUN(%)/ PEAK GUST/RMY GUST
RMY:  R.M. Young wind gust recording system
TSTM: Thunderstorm day (thunder heard some time during day)
....: Data not yet available, records not finalized
 
12/1  63/37/50/+13/0.01/0.0/391/70             28 WNW RMY 31
12/2  37/30/34/-2/0.10/T/000/00                26 E   RMY 29
12/3  49/34/42/+6/0.31/0.0/000/00              40 W   RMY 43
12/4  41/27/34/-1/0.00/0.0/505/91              29 WNW RMY N/A
12/5  42/23/33/-2/0.12/0.0/382/69              21 E   RMY 22
12/6  43/36/40/+5/0.99/0.0/000/00              25 NNW RMY N/A
12/7  36/18/27/-7/0.15/0.0/193/35              31 N   RMY 34
12/8  25/16/21/-13/0.01/0.1/000/00             24 N   RMY N/A
12/9  48/25/37/+3/3.23/0.0/000/00              48 ENE RMY 52
12/10 47/35/41/+8/0.43/0.0/000/00              35 NNE RMY 37
12/11 35/29/32/-1/0.05/0.5/000/00              27 SW  RMY 27 
12/12 36/26/31/-2/0.00/0.0/230/42              23 WNW RMY 25
12/13 40/27/34/+2/0.00/0.0/191/35              28 NW  RMY 28
12/14 43/28/36/+4/0.00/0.0/377/69              20 NW  RMY 20
12/15 41/28/35/+3/0.00/0.0/536/98              17 NW  RMY 17
12/16 42/33/38/+7/T/T/011/02                   17 E   RMY N/A
12/17 45/37/41/+10/0.43/0.0/000/00             27 W   RMY N/A
12/18 41/32/37/+6/0.02/T/213/39                35 WNW RMY 38  
12/19 34/25/30/0/0.00/0.0/000/00               26 NW  RMY 29
12/20 32/24/28/-2/..../.../.../..              21 NNE RMY 23
 
12/21 morning low temp: 29F since midnight; normal low is now 22F
 
DAILY RECORDS FOR DECEMBER 2014:
     
-DAILY PRECIPITATION RECORD FOR DECEMBER 9 2014
      Old record of 1.51 inches set in 1952,
      replaced with new record of 3.23 inches.
 
DAILY EXTREMES
Temperature and precipitation records back to 1885, and
wind records back to 1940 (e = estimated):    
 
RECORDS FOR DECEMBER 21
HIGH 60 IN 1957
LOW -10 IN 1942
PRECIP 2.01 INS. IN 1946
SNOWFALL 11.4 INS. IN 1954
PEAK GUST 77 MPH SSE IN 1957
 
RECORDS FOR DECEMBER 22
HIGH 62 IN 1994
LOW -5 IN 1921
PRECIP 1.52 INS. IN 1975
SNOWFALL 8.8 INS. IN 1975
PEAK GUST 62 MPH WNW IN 1998
 
TODAY'S REPORT PREPARED BY: Jonathan O'Brien